Here are a few articles discussing the power of .edu links.
Marko Nikolic says:
If you want to rank for a heavily competitive keyword try building some .edu back links and see how drastically it changes your rankings.
http://marko.gnosticdesigns.com/2008/02/28/why-i-love-edu-backlinks/
And on SEO Book, Aaron Wall explained the concept the same way we do, that it is not just about the .edu behind the domain, but the trusted nature of an EDU site.
I have a PageRank 7 site that doesn’t rank anywhere near as well as you would expect given its PageRank. I also have a couple PageRank 5 sites that rank for a ton of searches and are getting thousands of visits a day. One of them has less than 30 pages too. What do the PageRank 5 sites have that the PageRank 7 site lacks? Tons of .edu and librarian type links.
Proof Google Loves EDU & GOV Sites: http://www.seobook.com/archives/001816.shtml
And another SEO blogger discusses his reasons for trying to obtain .edu links:
“Having .edu links means that your site will gain more and more credibility”
SERoundtable covered this awhile ago as well:
Over the past year or so, it has been widely reported that links from .edu and .gov top level domains (TLD’s- like the more common .com or .org) carry more weight than others.
